Question

Sketch Feynman vertex for the annihilation of a b quark and $\overline{u}$.

Short answer

The Feynman diagram is shown in the figure as follows:

Step-by-step solution

Given data

The $\overline{u}$ has charge $\frac{-2}{3}$ and b has charge$\frac{-1}{3}$ .

Concept of Feynman diagram 

A Feynman diagram describes the interactions in quantum field theory. Solid lines and curved lines are used to represent different types of particle interactions.

Step 3:Sketch Feynman vertex

The Feynman diagram is shown in figure 1.

Figure 1

Because the type of quark changed, it is a weak interaction.

Because $\overline{u}$ has charge $\frac{-2}{3}$ and b has charge$\frac{-1}{3}$ , they will exchange a ${\text{W}}^{-}$boson.